Process for the protection of a tuyere of a refining converter

ABSTRACT

A process of protecting a tuyere of a refining converter having a double or multiple feed of which one, which may be the central feed, is pure oxygen, the process comprising feeding preferably a peripheral conduit with a viscous, a pasty, or powdery and compressed material containing carbon to protect the nose of the tuyere against wear by hot corrosion.

Leroy et al.

PROCESS FOR THE PROTECTION OF A TUYERE OF A REFINING CONVERTER Inventors: Pierre Leroy,

Saint-Germain-en-Laye; Emile Sprunck, Moyeuvre-Grande, both of France Assignee: Societe Creusot-Loire, Paris, France Filed: Sept. 7, 1972 Appl. No.: 286,936

Foreign Application Priority Data [451 Apr. 2, 1974 [56] References Cited UNITED STATES PATENTS 3,706,549 12/1972 Knuppel et al. 266/35 Primary ExaminerGerald A. Dost Attorney, Agent, or FirmCamer0n, Kerkam, Sutton, Stowell & Stowell [57] ABSTRACT A process of protecting a tuyere of a refining converter having a double or multiple feed of which one, which may be the central feed, is pure oxygen, the process comprising feeding preferably a peripheral conduit with a viscous, a pasty, or powdery and compressed material containing carbon to protect the nose of the tuyere against wear by hot corrosion.

9 Claims, No Drawings PROCESS FOR THE PROTECTION OF A TU YERE OF A REFINING CONVERTER The present invention relates to tuyeres of refining converters with separate, double or multiple feed, blowing an oxidizing gas, which may be pure oxygen, in the central conduit of the tuyere, while the peripheral annular conduit is fed by a substance protecting the nose of the tuyere against hot wear.

Gases or liquids are known which, fed into the peripheral conduits of such a tuyere, effectively protect the nose of the tuyere against hot wear. Thus the applicants have disclosed peripheral feed of a liquid containing hydrocarbons, such as fuel oil for example, which gives excellent stability of tuyeres and of converter bottoms, in which oxygen is blown.

But the employment of gases or liquids demands a tective agent which is easier to use than a gas or a liquid.

To this end, the present invention has as its object a process for protection of a tuyere of a refining converter with separate, double or multiple feed, blowing an oxidizing gas which may be pure oxygen through one of its conduits, which may be the central conduit, characterised by the feed of at least one other conduit of the tuyere, which may be the peripheral conduit or conduits, with a viscous, pasty, or powdery material, which is compressed, and which contain carbon, and more particularly heavy hydrocarbons, and protects the nose of the tuyere against hot wear.

According to a particular characteristic of the invention, the material which protects the tuyere against hot wear is a paste constituted by dissolution of a suitable proportion of paraffin in fuel oil.

Among the various suitable proportions is that which corresponds to raw vaseline.

According to another particular characteristic of the invention, the material which protects the tuyere against hot wear is constituted by residues from the treatment of crude mineral oils, such as semi-fluid pitches, or soft pitches, or hard pitches, or heavy or extra heavy fuel oil, or greases.

According to another characteristic of the invention, the material which protects the nose of the tuyere is constituted by coke in fine pieces, or pulverised and compressed.

According to another characteristic of the invention, the material which protects the nose of the tuyere is constituted by pulverised carbon in suspension in a fluid or pasty material.

According to another characteristic of the invention, the material which protects the nose of the tuyere is a dissolution in a suitable proportion of pitch or petroleum coke in fuel oil.

According to another characteristic of the invention, the material which protects the nose of the tuyere is a tar.

According to another characteristic of the invention, the material which protects the nose of the tuyere is a more or less pasty filling of tar and ofa refractory lining material in small fragments or in grains, which may be dolomite or magnesia or chalk, or any other suitable refractory material.

According to another characteristic of the invention, the flow of protective viscous, pasty or powdery material is controlled by any suitable mechanical, electrical or pneumatic means, such that it may be increased if appreciable wear of the tuyere appears and reduced if a partial obstruction of the tuyere is produced, deleteriously reducing the flow of oxidizing gas.

According to a variant of the process according to the invention, the protection of the tuyere with separate, triple or multiple feed is improved by the introduction of a third fluid, such as ordinary air, or a neutral gas, or steam, or water, for example, into an intermediate conduit between the central conduit of the tuyere blowing pure oxygen or an oxidizing gas and the peripheral conduit or conduits fed by the protective, viscous or pasty or powdery material, under pressure.

This variant of the invention has the effect of opposing any partial obstruction of the central conduit of the tuyere which may be produced when certain viscous or pasty materials are employed.

As will be understood, one of the main advantages of the invention as compared with known processes, is that'it does not use a liquid or gaseous fluid for the protection of the tuyere, but a substance of a consistency which is intermediate between the purely liquid state and the purely solid state, and which nevertheless is able to flow, i.e., a viscous, pasty or powdery substance, which is compressed; the compression ensures its advance into the tuyere to the extent of its consumption at the nose of the latter.

It follows that a mechanical or pneumatic means for compressing this substance is sufficient to ensure both the flow of the product into the tuyere and the control of the flow of the material.

In order that the process according to the invention may be well understood, an embodiment of the process according to the invention is described below, without thereby implying any limitation of the invention.

In a tuyere constituted by two concentric tubes, the inner tube having an inner diameter of 20 mm and an outer diameter of 25 mm, the outer tube having an inner diameter of 30 mm and an outer diameter of 35 mm, the two tubes being precisely centred one within the other in a conventional manner, pure oxygen is blown into the inner tube, at the rate of 25Nm /min at 12 bars, and crude vaseline is introduced into the outer tube at the rate of 1 kg per minute, by means of a greaser of conventional type, suitably regulated for the duration of at least one operation of refining in the converter. For a blow of 10 minutes, the consumption of vaseline per tuyere is thus 10 kg per operation. Thus for a converter receiving 25 tonnes of liquid iron, and with six tuyeres as described above in the bottom, the total consumption of vaseline is kg, i.e., about 2.5 Kg to the tonne of steel produced.

Variations and improvements of detail, and also the employment of equivalent means, may of course be used without departing from the scope of the invention.

We claim:

1. Process for the protection of a tuyere of a refining converter with multiple feed, the steps of blowing an oxidizing gas including pure oxygen, through one of its conduits, which may be the central conduit of the tuyere, and feeding at least one peripheral conduit of the tuyere with a carbon containing material selected from the group consisting of viscous hydrocarbons, pasty hydrocarbons and compressed powders containing carbon whereby the nose of the tuyere is protected against wear by hot corrosion.

2. Process for protection of a tuyere according to claim 1, the carbon containing material being a paste of paraffin in fuel oil.

3. Process for protection of a tuyere according to claim the material carbon containing being Vaseline.

4. Process for protection of a tuyere according to claim 1, the carbon containing material being residues from the treatment of crude mineral oils selected from the group consisting of semi-fluid pitches, soft pitches, hard pitches, heavy fuel oil, extra heavy fuel oil and greases.

5. Process for protection of a tuyere. according to claim 1, the carbon containing material compressed fragments.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORREQTION PATENT NO. I 3,801,084 DATED 1 April 2 197A INVENTOR(S) Pierre Leroy et al It is certified that error appears in the ab0veidentified patent and that said Letters Patent are hereby corrected as shown below:

[73] After Assignee:, insert -of an undivided one half interest.

Signed and Sealed this fifteenth Day Of June I976 [SEAL] Arrest:

RUTH C. MASON I C. MARSHALL DANN Arresting Officer Commissioner nfParenrs and Trademarks 

2. Process for protection of a tuyere according to claim 1, the carbon containing material being a paste of paraffin in fuel oil.
 3. Process for protection of a tuyere according to claim the material carbon containing being vaseline.
 4. Process for protection of a tuyere according to claim 1, the carbon containing material being residues from the treatment of crude mineral oils selected from the group consisting of semi-fluid pitches, soft pitches, hard pitches, heavy fuel oil, extra heavy fuel oil and greases.
 5. Process for protection of a tuyere according to claim 1, the carbon containing material compressed powdered coke.
 6. Process for protection of a tuyere according to claim 1, the carbon containing material being pulverized carbon in suspension.
 7. Process for protection of a tuyere according to claim 1, the carbon containing material being petroleum coke in fuel oil.
 8. Process for protection of a tuyere according to claim 1, the carbon containing material being tar.
 9. Process for protection of a tuyere according to claim 1, the carbon containing material being a pasty filling of tar and of a refractory lining material in small fragments. 